I've been looking into starting a dirt tank, and I'm wondering why you have to 'cap' it with sand or gravel? Also curious about using mud instead of topsoil . . .

Any advice or information on this would be greatly appreciated! I still have a lot of research to do here! :-D

Boredomb

02-23-2013 12:47 AM

Jes all I am saying is YOU need to do one as you have the tanks for it and I know you have the time for such a project! LMAO!

Chesh

02-23-2013 01:05 AM

Yeah, you're a reeeaaaaaal funny guy, John ;) I WILL have *some* time. . . after I shut down, like, four tanks or so. . . since I'm already considering setting up a breeding tank for my rams, might as well make it 2 in 1, neh? Or... maybe not. Rams LIKE sand. But I DO have a plant only QT tank. . .hrm

I'm really wanting to try a dirt tank. . . eventually the plan is to move Becoming into a 125 or so, and though that's some time down the road, you know what a planner I am! I'm considering substrates, and am very interested in the concept of dirt or mud. . . but I think this is something that I'll really need to try out in a smaller tank before committing to something so huge!

Even if it's not the best plan for the bigger tank, I'd like to give it a try, anyway. So I know. . .I just don't understand why the caps? I think a plain ol' dirt or mud bottom would look nice - but nobody does it? Why!?

jentralala

02-23-2013 01:06 AM

I'm not suuuper familiar with dirt tanks, but from my experiments with bottles/containers, the cap is necessary to stop the light particles of the soil from floating all over the place and making the water black and icky. When you cap it, it prevents the soil from just floating all over the tank. And it being soil, it's kind of impossible to 'rinse' the fine particles out. I've 'capped' with both sand and gravel. It almost acts as a filter, when you fill the container. It traps all of the particles beneath it.

Another thing I can think of off the top of my head is that dirt tanks require a lot of time to stabilize and be safe for fish. Something about the soil producing a lot of ammonia/CO2.

What do you mean by mud? I'm always tossing around the idea of using sand from the lake in a biotope aquarium, but there is so much other gunk and creepy eepy crawlies in there that I'm a bit terrified of doing so, lmao.

Chesh

02-23-2013 01:14 AM

Thanks Jen! I suspected that floaty bits would have something to do with it - but wouldn't these particles eventually be filtered out?

As far as ammonia/Co2 - like you said, it takes time to stabilize - regardless of a 'cap.' So. . . that *shouldn't* apply, right? Or not. . . *shrugs*

I mean mud, lol! Yeah. . . creepy crawlies. . . but if the mud were, I dunno, boiled and baked before putting it into the tank, wouldn't it be okay eventually? *scratches head*

I'm about to re-read my D.Walstad and P.Hiscock books, maybe I missed some info in there the last time around - I was just reading to learn, not intending to actually set one up at that time. I'm in no rush to add stock, so time isn't a factor. I just want to understand before I get started.

Chesh

02-23-2013 08:39 AM

Been looking through threads on other plant-related forums. . . it is done, and done well, from what I've read so far. I may have to give this method a try on one of my soon-to-be empty 10g tanks and see how it goes. I can start with a plant-only tank while things are settling, and if all goes well lightly stock after some time has passed. Still have a LOT of research to do.

Any input welcome!

redchigh

02-23-2013 09:40 PM

I pmed you, but.. a sand or gravel cap only speeds up the process that would happen naturally: nearly all soil contains sand or gravel, and over time clay sinks and most of the silt washes away, which leaves a clay-rich capped substrate...Posted via Mobile Device

Chesh

02-23-2013 10:40 PM

Quote:

Originally Posted by redchigh
(Post 1442386)

I pmed you, but.. a sand or gravel cap only speeds up the process that would happen naturally: nearly all soil contains sand or gravel, and over time clay sinks and most of the silt washes away, which leaves a clay-rich capped substrate...Posted via Mobile Device

Thanks for your input, and your PM, Redchigh. I really appreciate your input here, as I know you're one of our resident experts when it comes to dirty tanks!

Interesting point you bring up about the natural process of things. . . and I agree that their is separation that happens, but the rivers and streams around here don't so much have 'sand' It may be a coarser grain of something or another though. I'll have to pay more attention the next time I take a journey out!

Either way, would there be any issues with letting this process happen on it's own, and not capping it to begin with? If I mineralise the soil heavily, as you recommended (and as I'd be inclined to do, anyway) and then sifted it, would the tank still be a dirt-covered mess for a very long time? Or is it something that would more or less settle fairly quickly? You did say in your PM that it could take months to clear without a cap, but is there any way around this? I saw a 'test' somewhere along the line of my reading the other night where you shake some soil in a jar and mark the levels of settling at 1 hour 2 hours, overnight, etc. During the process of mineralization, wouldn't a LOT of the silt get washed away, leaving the heavier, but smaller, bits that WOULD settle more quickly?

I can be patient, this is more about experimenting and seeing what happens than actually having any particular goal in mind. . . though I would like to NOT end up with an algae-covered muddy water tank if at all possible, lol!

From what I'm seeing on other forums, mixing the soil with clay helps in the settling process. I believe most people say 10%? You mentioned in your PM that you'd recommend that I mix the soil 50 - 50 with sand. What if I didn't? Could I actually JUST use the soil and have it work out? Or do the plant roots need that heavier sand to hold them down and into the substrate?

So much left to learn - thanks for lending the benefit of your experience!

redchigh

02-24-2013 12:38 AM

its surely not "play sand", but its a particulate of stone and minerals... essentially, sand. ;)

If its slow moving, the water will likely have more silt, but be less clear.

If you want it to be all natural, you could seperate your soil in order to have the layers form faster... Clay makes the substrate heavier, and inhibits water flow throw the substrate, which 1, keeps the water clearer (as long as its not stirred up), and 2, encourages anaerobic bacteria and the possibly lethal buildup of hydrogen sulfide and co2 bubbles. (bubbles of harmless co2 can also stir the substrate when it burps, causing cloudiness....)

during the settling process, use a powerful filter (that wont disturb the substrate) along with an airstone. After a week or two, remove the airstone, test the params and if they're good, add fish.

You want some clay in the soil, but most soil has clay in it.

After all, worst case scenario is drain the tank, cap with sand, and refill.

Chesh

02-24-2013 07:21 AM

Quote:

Originally Posted by redchigh
(Post 1442674)

its surely not "play sand", but its a particulate of stone and minerals... essentially, sand. ;)

Heehee, I getcha - and that is exactly what I want! So then. . . over time, the soil will cap itself, and in theory, keep it from being a mess forever. . . will the silt eventually settle/filter out?

Quote:

Originally Posted by redchigh
(Post 1442674)

Clay makes the substrate heavier, and inhibits water flow throw the substrate, which 1, keeps the water clearer (as long as its not stirred up), and 2, encourages anaerobic bacteria and the possibly lethal buildup of hydrogen sulfide and co2 bubbles.

You just made using clay sound really scary . . . the clearer water part, I'm down with! The possibly lethal buildup. . .not so much! With my sand tank,s I have my little MTS happily digging away in order to prevent these things from happening, and in the few areas where I have no plant roots to help me, I sift the sand every few months to keep any anaerobic pockets from forming. . . I suppose I won't be able to sift the soil without causing a ruckus - is this something that I should be worried about over time? Can MTS help here? Hmmmmmm... don't want to kill anyone, though I'm sure I'll be waiting longer than a week or two before adding any fish - just to be sure!

Quote:

Originally Posted by redchigh
(Post 1442674)

You want some clay in the soil, but most soil has clay in it.

If most soil has clay in it. . . should I add more or not? In most of the personal accounts I've seen, people are adding 5 - 10% of a natural clay to the soil before putting it into the tank. I'd probably mix everything in and watch it settle into layers naturally - that's something that I'd enjoy. . .

Quote:

Originally Posted by redchigh
(Post 1442674)

After all, worst case scenario is drain the tank, cap with sand, and refill.

*nods* No harm, no foul, eh? This is going to be fun. . . I'm going to re-read some of my planting books, especially Walstad, re-read YOUR guide, and find as many tank logs as I can, so that I can get a bit of a better concept behind exactly what will be going on during this process. . . thank you for all of your help!!! I'm sure I'll have many more questions before I'm ready to go!